Malicious PDF — malware analysis report

Static analysis result for SHA-256 81bcdec04e92b927…

MALICIOUS

PDF

48.4 KB Created: 2020-07-31 15:26:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0d45802735c00a52f67b8f2f4d607bfc SHA-1: ed56e151580e47cf282e64c5b2c7f9bf441bc5fd SHA-256: 81bcdec04e92b927f88f7b45870ba9148a0e14907625667d75c20fab26e96dce
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded links, with a critical heuristic firing for PDF_MALICIOUS_REDIRECTOR_LINK pointing to `https://ttraff.cc/pify?keyword=unix+command+cheat+sheet`. This indicates the document is designed to redirect users to potentially malicious content, disguised as a useful cheat sheet. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ttraff.cc/pify?keyword=unix+command+cheat+sheet
    • http://files.celebrationcatering.net/uploads/1/3/1/1/131163736/kutenuzagibaselu.pdf
    • http://files.coupevillelions.org/uploads/1/3/2/6/132682281/8316978.pdf
    • http://files.dominickmscialabba.com/uploads/1/3/0/9/130969993/sebafep-widemej.pdf
    • http://files.morethansoulfood.com/uploads/1/3/0/7/130738876/vidorot.pdf
    • http://files.murphymedicalwriting.com/uploads/1/3/0/8/130873838/fevewili-rumujez-batex.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0439/6898/7294/files/auto_tunes_torrent.pdf
    • https://cdn.shopify.com/s/files/1/0432/3190/3902/files/41546765921.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/85484739365.pdf
    • https://cdn.shopify.com/s/files/1/0431/5165/5076/files/surilodimibid.pdf
    • https://cdn.shopify.com/s/files/1/0427/7963/9967/files/nazepito.pdf
    • https://cdn.shopify.com/s/files/1/0431/2514/5760/files/kiwafumugufesawave.pdf
    • https://cdn.shopify.com/s/files/1/0434/0567/2597/files/vumenekukikosugebiz.pdf
    • https://cdn.shopify.com/s/files/1/0438/4302/7104/files/mexowunasorizezesow.pdf
    • https://cdn.shopify.com/s/files/1/0434/0174/0439/files/55764788095.pdf
    • https://cdn.shopify.com/s/files/1/0432/8180/9558/files/77992231083.pdf
    • https://cdn.shopify.com/s/files/1/0431/7036/5602/files/pelurobuzubujag.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007f1a.bin
578db8cda080355194070620aec6271ef0d313ae37b1a0c9a8758a250f0c732c
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F1A 4896 bytes
font_01_sfnt_off00008f8d.bin
d4cf0419d5c17222e6aed662dc424d1d794dedd92a06b0521f904daeb82c0d18
pdf-font-stream PDF embedded font (sfnt) at offset 0x8F8D 10996 bytes